guardar desde indesign un pdf para illustrator con imagenes vinculadas y no incrustadas

InDesign PDFs are not supposed to be opened in Illustrator. Therefore images are always embedded.

To get the same quality as the linked images, do not use any recalculation or compression in PDF export.

Are you using the settings for High Quality Print (File>Adobe PDF Presets>[High Quality Print]) when you create your PDF from InDesign? The Press Quality preset also usually gives excellent results.

Of course, the quality of your images in an exported PDF is entirely dependent on how good those images are in the original InDesign file. Exporting to PDF will not improve a poor or pixelated image.

There are no "linked" images in PDF, all images are embedded in the PDF document.

Why they're low quality in your PDF is a different question.

First, can you please post a screenshot of the Compression settings of your PDF export settings.